Formulation and evaluation of anion transporters in nanostructured lipid carriers.

Six novel click-tambjamines (1-6) bearing an alkyl chain of varying length linked to the imine moiety have been formulated in nanostructured lipid carriers (NLCs) to evaluate their transmembrane anion transport activity both when free (i.e., not encapsulated) and nanoformulated. Nanostructured lipid carriers (NLCs) are an example of drug delivery systems (DDSs) that stand out because of their versatility. In this work we show that NLCs can be used to efficiently formulate highly lipophilic anionophores and experiments conducted in model liposomes reveal that these formulations are adequate to deliver anionophores without compromising their transport activity. This result paves the way to facilitate the study of highly lipophilic anionophores and their potential use as future drugs.

Colistin- and amikacin-loaded lipid-based drug delivery systems for resistant gram-negative lung and wound bacterial infections.

Antimicrobial resistance (AMR) is a global health issue, which needs to be tackled without further delay. The World Health Organization(WHO) has classified three gram-negative bacteria, Pseudomonas aeruginosa, Klebsiella pneumonia and Acinetobacter baumannii, as the principal responsible for AMR, mainly causing difficult to treat nosocomial lung and wound infections. In this regard, the need for colistin and amikacin, the re-emerged antibiotics of choice for resistant gram-negative infections, will be examined as well as their associated toxicity. Thus, current but ineffective clinical strategies designed to prevent toxicity related to colistin and amikacin will be reported, highlighting the importance of lipid-based drug delivery systems (LBDDSs), such as liposomes, solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), as efficient delivery strategies for reducing antibiotic toxicity. This review reveals that colistin- and amikacin-NLCs are promising carriers with greater potential than liposomes and SLNs to safely tackle AMR, especially for lung and wound infections.

Improvement of Cell Culture Methods for the Successful Generation of Human Keratinocyte Primary Cell Cultures Using EGF-Loaded Nanostructured Lipid Carriers.

Human skin keratinocyte primary cultures can be established from skin biopsies with culture media containing epithelial growth factor (EGF). Although current methods are efficient, optimization is required to accelerate the procedure and obtain these cultures in less time. In the present study, we evaluated the effect of novel formulations based on EGF-loaded nanostructured lipid carriers (NLC). First, biosafety of NLC containing recombinant human EGF (NLC-rhEGF) was verified in immortalized skin keratinocytes and cornea epithelial cells, and in two epithelial cancer cell lines, by quantifying free DNA released to the culture medium. Then we established primary cell cultures of human skin keratinocytes with basal culture media (BM) and BM supplemented with NLC-rhEGF, liquid EGF (L-rhEGF), or NLC alone (NLC-blank). The results showed that cells isolated by enzymatic digestion and cultured with or without a feeder layer had a similar growth rate regardless of the medium used. However, the explant technique showed higher efficiency when NLC-rhEGF culture medium was used, compared to BM, L-rhEGF, or NLC-blank. Gene expression analysis showed that NLC-rhEGF was able to increase EGFR gene expression, along with that of other genes related to cytokeratins, cell-cell junctions, and keratinocyte maturation and differentiation. In summary, these results support the use of NLC-rhEGF to improve the efficiency of explant-based methods in the efficient generation of human keratinocyte primary cell cultures for tissue engineering use.

Generation of a novel human dermal substitute functionalized with antibiotic-loaded nanostructured lipid carriers (NLCs) with antimicrobial properties for tissue engineering.

BACKGROUND: Treatment of patients affected by severe burns is challenging, especially due to the high risk of Pseudomonas infection. In the present work, we have generated a novel model of bioartificial human dermis substitute by tissue engineering to treat infected wounds using fibrin-agarose biomaterials functionalized with nanostructured lipid carriers (NLCs) loaded with two anti-Pseudomonas antibiotics: sodium colistimethate (SCM) and amikacin (AMK). RESULTS: Results show that the novel tissue-like substitutes have strong antibacterial effect on Pseudomonas cultures, directly proportional to the NLC concentration. Free DNA quantification, WST-1 and Caspase 7 immunohistochemical assays in the functionalized dermis substitute demonstrated that neither cell viability nor cell proliferation were affected by functionalization in most study groups. Furthermore, immunohistochemistry for PCNA and KI67 and histochemistry for collagen and proteoglycans revealed that cells proliferated and were metabolically active in the functionalized tissue with no differences with controls. When functionalized tissues were biomechanically characterized, we found that NLCs were able to improve some of the major biomechanical properties of these artificial tissues, although this strongly depended on the type and concentration of NLCs. CONCLUSIONS: These results suggest that functionalization of fibrin-agarose human dermal substitutes with antibiotic-loaded NLCs is able to improve the antibacterial and biomechanical properties of these substitutes with no detectable side effects. This opens the door to future clinical use of functionalized tissues.

Compliance of nutritional recommendations of spanish pregnant women according to sociodemographic and lifestyle characteristics: a cohort study / Cumplimiento de las recomendaciones nutricionales de mujeres embarazadas en España en relación a sus características sociodemográficas: estudio de una cohorte

Objective: To assess nutrient intakes and compliance with nutritional recommendations in pregnant women according to selected sociodemographic characteristics and lifestyles. Methods: Cross-sectional study based on data from Spanish INMA cohort which recruited 2,585 pregnant women between 2003 and 2008 from four different regions of Spain. Sociodemographic information and anthropometry was collected and dietary intake was assessed through Food Frequency Questionnaires. The adequacy of food group intake was assessed considering current recommendations and from the Spanish Society of Nutrition. Moreover, intake of vitamin A, vitamin C and vitamin E, were compared with the Dietary Reference Intakes of the US Institute of Medicine. Results: Percentage of women that did not fulfil the recommendations for cereals and legumes (3-4 servings/ day) was 70.0%, for fruit intake (2-3 servings/day) it was 39.2%, for vegetables (2-4 servings/day) 47.3% and for dairy (3-4 servings/day) it was 51.6%. Intake of fruit and vegetables increased with age, educational degree and with physical activity (p<0.005). Also non-Spanish achieved better the recommendations. Percentage of pregnant women that did not fulfil the requirements (DRI) of vitamins A and C was 13.2 % and 16.2 respectively. More than 65% of the women did not met the recommended diary intake of vitamin E of 19 mg/day during the lactation period. Conclusions: Maternal age, education, having healthy habits, as well as country of origin are factors strongly associated with the composition of the diet. Sedentary women and those with a low education are at risk for low vitamin and antioxidant intake and non-optimal food choices during pregnancy (AU)

Objetivo: Estudiar las ingesta dietética y cumplimiento de las recomendaciones nutricionales de una población de mujeres embarazadas, de acuerdo a sus características sociodemográficas y hábitos de vida. Métodos: se trata de un estudio prospectivo basado en datos de la cohorte española INMA (Infancia y Medioambiente). Se han reclutado 2.585 mujeres embarazadas entre los años 2003 y 2008 en cuatro regiones diferentes de España. La ingesta dietética ha sido recogida mediante Cuestionarios de Frecuencia Alimentaria (CFA) y la información antropométrica, sociodemográfica y de estilos de vida a través de cuestionarios generales. La ingesta de grupos de alimentos y de vitaminas A, C y E y carotenoides fueron comparadas con las ingestas dietéticas de referencia de las guías Española y Americana. Resultados: El porcentaje de mujeres embarazadas que no cumplían las recomendaciones de cereales y legumbres (3-4 raciones /día) fue del 70 %, de frutas (2-3 raciones /día) el 39,2%, de verduras (2-4 raciones /día) fue del 47,3% y de lácteos (3-4 raciones /día) el 51,6%. La ingesta de frutas y verduras fue mayor en mujeres extranjeras y aumento con la edad, con el nivel de estudios y en mujeres con mayor actividad física (p<0.005). El porcentaje de mujeres embarazadas que no cumplieron los requerimientos (CDR) de vitaminas A y C fueron el 13,2% 16, 2% respectivamente. Más del 65% de las mujeres no cumplieron el mínimo de ingesta de vitamina E (19 mg/día) recomendado para mujeres embarazadas y en periodo de lactancia. Conclusiones: En este estudio se ha observado que factores como la edad, educación, tener hábitos de vida saludables así como el país de origen están fuertemente asociados a la composición de la dieta en las mujeres embarazadas. Mujeres sedentarias y con bajo nivel educativo tienen ingesta más bajas de vitaminas y antioxidantes procedentes de las frutas y verduras y por lo tanto más riesgo de llevar una dieta poco adecuada durante el embarazo (AU)

Compliance of nutritional recommendations of Spanish pregnant women according to sociodemographic and lifestyle characteristics: a cohort study.

OBJECTIVE: To assess nutrient intakes and compliance with nutritional recommendations in pregnant women according to selected sociodemographic characteristics and lifestyles. METHODS: Cross-sectional study based on data from Spanish INMA cohort which recruited 2,585 pregnant women between 2003 and 2008 from four different regions of Spain. Sociodemographic information and anthropometry was collected and dietary intake was assessed through Food Frequency Questionnaires. The adequacy of food group intake was assessed considering current recommendations and from the Spanish Society of Nutrition. Moreover, intake of vitamin A, vitamin C and vitamin E, were compared with the Dietary Reference Intakes of the US Institute of Medicine. RESULTS: Percentage of women that did not fulfil the recommendations for cereals and legumes (3-4 servings/day) was 70.0%, for fruit intake (2-3 servings/day) it was 39.2%, for vegetables (2-4 servings/day) 47.3% and for dairy (3-4 servings/day) it was 51.6%. Intake of fruit and vegetables increased with age, educational degree and with physical activity (p<0.05). Also non-Spanish achieved better the recommendations. Percentage of pregnant women that did not fulfil the requirements (DRI) of vitamins A and C was 13.2 % and 16.2 respectively. More than 65% of the women did not met the recommended diary intake of vitamin E of 19 mg/day during the lactation period. CONCLUSIONS: Maternal age, education, having healthy habits, as well as country of origin are factors strongly associated with the composition of the diet. Sedentary women and those with a low education are at risk for low vitamin and antioxidant intake and non-optimal food choices during pregnancy.

Objetivo: Estudiar las ingesta dietética y cumplimiento de las recomendaciones nutricionales de una población de mujeres embarazadas, de acuerdo a sus características sociodemográficas y hábitos de vida. Métodos: se trata de un estudio prospectivo basado en datos de la cohorte española INMA (Infancia y Medioambiente). Se han reclutado 2.585 mujeres embarazadas entre los años 2003 y 2008 en cuatro regiones diferentes de España. La ingesta dietética ha sido recogida mediante Cuestionarios de Frecuencia Alimentaria (CFA) y la información antropométrica, sociodemográfica y de estilos de vida a través de cuestionarios generales. La ingesta de grupos de alimentos y de vitaminas A, C y E y carotenoides fueron comparadas con las ingestas dietéticas de referencia de las guías Española y Americana. Resultados: El porcentaje de mujeres embarazadas que no cumplían las recomendaciones de cereales y legumbres (3-4 raciones /día) fue del 70 %, de frutas (2-3 raciones /día) el 39,2%, de verduras (2-4 raciones /día) fue del 47,3% y de lácteos (3-4 raciones /día) el 51,6%. La ingesta de frutas y verduras fue mayor en mujeres extranjeras y aumento con la edad, con el nivel de estudios y en mujeres con mayor actividad física (p.

Ensayo de formación y cuantificación de biopelículas mixtas de Candida albicans y Staphylococcus aureus / Formation and quantification assay of Candida albicans and Staphylococcus aureus mixed biofilm

En el presente estudio se cuantificó la producción de biopelículas individuales y mixtas de Candida albicans y Staphylococcus aureus para determinar si dichas biopelículas mixtas se favorecen sinérgicamente. Los ensayos se realizaron utilizando placas de microtitulación de poliestireno de 96 pocillos de fondo plano, se determinó la actividad metabólica de las células en la biopelícula por medio de la reducción enzimática de una sal de tetrazolio (XTT) a través de los cambios colorimétricos que fueron medidos a 490nm. Para visualizar las biopelículas de cada microorganismo y su cinética de crecimiento se utilizo microscopia láser confocal. La mayor formación de biopelícula se observó en las biopelículas mixtas, seguida de las de Candida albicans y, por último, la menor producción la obtuvo Staphylococcus aureus, lo cual nos sugiere la presencia de una relación sinérgica entre los microorganismos ensayados(AU)

This study quantifies the production of single and mixed biofilms of Candida albicans and Staphylococcus aureus to determine if such mixed biofilms have synergistic effects. Assays were performed using polystyrene microtitre plates of 96 wells, metabolic activity was measured by the enzymatic reduction of a tetrazolium salt (XTT) and colorimetric changes were measured at 490nm. Confocal scanning laser microscopy was used to visualise the biofilms of each microorganism and its growth kinetics. The highest levels of biofilm formation were observed in mixed biofilms, followed by those of Candida albicans only, with the lowest levels of biofilm formation being detected for Staphylococcus aureus; all together these results suggest a synergistic relationship between the tested microorganisms(AU)

[Formation and quantification assay of Candida albicans and Staphylococcus aureus mixed biofilm]. / Ensayo de formación y cuantificación de biopelículas mixtas de Candida albicans y Staphylococcus aureus.

This study quantifies the production of single and mixed biofilms of Candida albicans and Staphylococcus aureus to determine if such mixed biofilms have synergistic effects. Assays were performed using polystyrene microtitre plates of 96 wells, metabolic activity was measured by the enzymatic reduction of a tetrazolium salt (XTT) and colorimetric changes were measured at 490 nm. Confocal scanning laser microscopy was used to visualise the biofilms of each microorganism and its growth kinetics. The highest levels of biofilm formation were observed in mixed biofilms, followed by those of Candida albicans only, with the lowest levels of biofilm formation being detected for Staphylococcus aureus; all together these results suggest a synergistic relationship between the tested microorganisms.

Variation in biofilm formation among blood and oral isolates of Candida albicans and Candida dubliniensis.

INTRODUCTION: Biofilm production is considered a potential virulence factor of some Candida species. For this reason, an understanding of biofilm behavior of Candida albicans and its closely related species Candida dubliniensis is key to the development of effective preventive measures for invasive and oral candidiasis. The aim of this study was to compare the capacity of biofilm production by blood and oral isolates of C. albicans and C. dubliniensis using polystyrene, flat-bottomed 100-well microtiter plates. METHODS: A total of 47 isolates, consisting of 28 C. albicans (16 oral and 12 blood isolates) and 19 C. dubliniensis (11 oral and 8 blood isolates) were compared for their biofilm forming ability under aerobic and static conditions. XTT reduction assay was used to quantify the sessile growth. RESULTS: All tested isolates produced biofilm, measured as XTT metabolic activity. Biofilm formation by C. albicans isolates was statistically significantly higher than biofilm formation by C. dubliniensis isolates at 24h (P=0.03) and 48 h (P=0.0001). There was a higher percentage (41.7%) of high producers of biofilms among C. albicans blood isolates than among oral isolates (31.3%), without statistically significant differences. CONCLUSIONS: This capability may allow C. albicans and C. dubliniensis to maintain their oral ecological niches as commensal or pathogenic microorganisms and can be a major virulence factor during invasive candidiasis. However, the differences in biofilm production among isolates should be taken into account when the anti-biofilm activity of antifungal agents or other virulence factors are tested in vitro.

Variation in biofilm formation among blood and oral isolates of Candida albicansand Candida dubliniensis

Introducción: El desarrollo de biopelículas o biocapas se considera un factor de virulencia potencial de algunas especies de Candida. Una comprensión mejor del comportamiento de las biopelículas de Candida albicans y de la especie cercana Candida dubliniensis es clave para desarrollar medida preventyivas eficaces de las candidiasis superficiales (orales) e invasoras. El objetivo de este trabajo ha sido comparar la capacidad de producir biopelícula por parte de los aislamientos orales y de sangre de C. albicans y C. dubliniensis en placas de microtitulación de poliestireno de 100 pocillos con fondo plano. Métodos: Se estudiaron 47 aislamientos: 28 C. albicans (16 orales y 12 hemáticos) y 19 C. dubliniensis(11 orales y 8 hemáticos). Se empleó una prueba de cuantificación de la actividad metabólica de las biopelículas (reducción de la sal de tetrazolio denominada XTT).Resultados: Todos los aislamientos mostraron actividad metabólica pero la formación de biopelícula por los aislamientos de C. albicans era significativamente mayor que por los de C. dubliniensis a 24h(P = 0,03) y 48 h (P = 0,0001). Eran más numerosos, los aislamientos de C. albicans muy productores de biopelícula procedentes de sangre (41.7%) que de boca (31.3%) pero las diferencias no eran significativas. Conclusiones: La capacidad de desarrollar biopelículas, podría permitir a C. albicans y C. dubliniensis mantenerse en el nicho oral como comensales o patógenos y ser un importante factor de virulencia en las candidiasis invasoras. Sin embargo, las diferencias encontradas entre los aislamientos productores debio película deben tenerse en cuenta, sobre todo en los estudios in vitro de virulencia o de la acciónanti-biopelícula de los fármacos antifúngicos (AU)

Introduction: Biofilm production is considered a potential virulence factor of some Candida species. For this reason, an understanding of biofilm behavior of Candida albicans and its closely related species Candida dubliniensis is key to the development of effective preventive measures for invasive and oral candidiasis. The aim of this study was to compare the capacity of biofilm production by blood and oralisolates of C. albicans and C. dubliniensis using polystyrene, flat-bottomed 100-well microtiter plates. Methods: A total of 47 isolates, consisting of 28 C. albicans (16 oral and 12 blood isolates) and 19 C.dubliniensis (11 oral and 8 blood isolates) were compared for their biofilm forming ability under aerobic and static conditions. XTT reduction assay was used to quantify the sessile growth. Results: All tested isolates produced biofilm, measured as XTT metabolic activity. Biofilm formation byC. albicans isolates was statistically significantly higher than biofilm formation by C. dubliniensis isolatesat 24 h (P = 0.03) and 48 h (P = 0.0001). There was a higher percentage (41.7%) of high producers of biofilms among C. albicans blood isolates than among oral isolates (31.3%), without statistically significant differences. Conclusions: This capability may allow C. albicans and C. dubliniensis to maintain their oral ecologicalniches as commensal or pathogenic microorganisms and can be a major virulence factor during invasive candidiasis. However, the differences in biofilm production among isolates should be taken into account when the anti-biofilm activity of antifungal agents or other virulence factors are tested in vitro (AU)

[Activity of micafungin against Candida biofilms]. / Actividad de la micafungina contra las biopelículas de Candida.

BACKGROUND: Most recalcitrant infections are associated to colonization and microbial biofilm development. These biofilms are difficult to eliminate by the immune response mechanisms and the current antimicrobial therapy. AIM: To describe the antifungal of micafungin against fungal biofilms based in the scientific and medical literature of recent years. METHODS: We have done a bibliographic retrieval using the scientific terms "micafungin", "activity", "biofilm", "Candida", "Aspergillus", "fungi", "mycos"*, susceptibility, in PubMed/Medline from the National Library of Medicine from 2006 to 2009. RESULTS: Most current antifungal agents (amphotericin B and fluconazole) and the new azole antifungals have no activity against fungal biofilms. However, micafungin and the rest of echinocandins are very active against Candida albicans, Candida dubliniensis, Candida glabrata, and Candida krusei biofilms but their activities are variable and less strong against Candida tropicalis and Candida parapsilosis biofilms. Moreover, they have not activities against the biofilms of Cryptococcus y Trichosporon. CONCLUSIONS: The activity of micafungin against Candida biofilms gives more strength to its therapeutic indication for candidaemia and invasive candidiasis associated to catheter, prosthesis and other biomedical devices.

Actividad de la micafungina contra las biopelículas de Candida / Activity of micafungin against Candida biofilms

Antecedentes: Muchas de las micosis más recalcitrantes al tratamiento se asocian a la colonización y la formación de biopelículas que son difíciles de eliminar por parte de los mecanismos defensivos inmunológicos y con el tratamiento antimicrobiano habitual. Objetivo: Describir la utilidad de la micafungina en las biopelículas fúngicas a partir de los datos publicados en los últimos años. Métodos: Se ha realizado una búsqueda bibliográfica mediante el empleo de los términos “micafungin”, “activity”, “biofilm”, “Candida”, “Aspergillus”, “fungi”, “mycos*”, “susceptibility”, en la base de datos PubMed/Medline de la National Library of Medicine de Estados Unidos desde enero de 2006 hasta enero de 2009. Resultados: La mayoría de los antifúngicos convencionales (anfotericina B y fluconazol) y los nuevos azoles no tienen actividad en las biopelículas fúngicas. Sin embargo, la micafungina y las otras equinocandinas son muy activas en las biopelículas de Candida albicans, Candida dubliniensis, Candida glabrata y Candida krusei, mientras que su actividad es variable con las de Candida parapsilosis y Candida tropicalis. Sin embar- go, su actividad es prácticamente nula contra las biopelículas de Cryptococcus y Trichosporon. Conclusiones: La actividad antifúngica de la micafungina en las biopelículas de Candida refuerza su indicación terapéutica en el tratamiento de las candidemias y candidiasis invasoras asociadas a catéteres, prótesis y otros implantes biomédicos (AU)

Background: Most recalcitrant infections are associated to colonization and microbial biofilm development. These biofilms are difficult to eliminate by the immune response mechanisms and the current antimicrobial therapy. Aim: To describe the antifungal of micafungin against fungal biofilms based in the scientific and medical literature of recent years. Methods: We have done a bibliographic retrieval using the scientific terms “micafungin”, “activity”, “biofilm”, “Candida”, “Aspergillus”, “fungi”, “mycos”*, susceptibility, in PubMed/Medline from the National Library of Medicine from 2006 to 2009. Results: Most current antifungal agents (amphotericin B and fluconazole) and the new azole antifungals have no activity against fungal biofilms. However, micafungin and the rest of echinocandins are very active against Candida albicans, Candida dubliniensis, Candida glabrata, and Candida krusei biofilms but their activities are variable and less strong against Candida tropicalis and Candida parapsilosis biofilms. Moreover, they have not activities against the biofilms of Cryptococcus y Trichosporon. Conclusions: The activity of micafungin against Candida biofilms gives more strength to its therapeutic indication for candidaemia and invasive candidiasis associated to catheter, prosthesis and other biomedical devices (AU)

Comparative evaluation of ATB Fungus 2 and Sensititre YeastOne panels for testing in vitro Candida antifungal susceptibility.

ATB Fungus 2 and SensititreYeastOne are commercial methods for antifungal susceptibility testing of yeasts. The agreement between these two methods was assessed with a total of 133 Candida strains (60 Candida albicans, 18 Candida dubliniensis, 29 Candida glabrata, and 26 Candida krusei). MIC endpoints were established after 24 h of incubation at 36-/+1 degrees C by each method. Intra-laboratory reproducibility of both methods was excellent (=or>99%). Overall agreement between ATB Fungus 2 and Sensititre YeastOne 3 MICs (within 2 dilutions) was 91.2-97.7% for amphotericin B, 5-fluorocytosine and itraconazole, and 82.7% for fluconazole. The categorical agreement when ATB Fungus 2 results were compared to those by SensititreYeastOne 3 was 93.2-98.5% for 5-fluorocytosine and amphotericin B, but lower for the triazoles (72.9-75.9%). This easy to perform method could be an alternative for routine use in the clinical microbiology laboratory for susceptibility testing of common Candida spp.

Activities of fluconazole and voriconazole against bloodstream isolates of Candida glabrata and Candida krusei: a 14-year study in a Spanish tertiary medical centre.

The aim of this study was to evaluate the in vitro activities of voriconazole and fluconazole against Candida glabrata and Candida krusei isolated from blood during a 14-year period (1990-2003) at the tertiary care hospital of Cruces (Barakaldo, Spain). The in vitro activities of fluconazole and voriconazole against 28 isolates of C. glabrata and 15 isolates of C. krusei were determined by the Clinical and Laboratory Standards Institute disk diffusion method. Of the 28 C. glabrata isolates tested, 24 (85.7%) were susceptible (S) to fluconazole, 2 (7.1%) were susceptible dose-dependent (S-DD) and 2 (7.1%) were resistant (R). All C. krusei isolates were classified as R to fluconazole. Resistance to voriconazole was observed in one isolate each of C. glabrata (3.6%) and C. krusei (6.7%), and one isolate of each species was S-DD. These results were confirmed by the Sensititre YeastOne and Etest methods, with good comparative results. Voriconazole was very active in vitro against C. glabrata and C. krusei blood isolates and the resistance observed was not related to the introduction of voriconazole in the therapeutic schedule of the hospital. These facts support the usefulness of voriconazole as a therapeutic tool for candidaemia caused by these species.

Comparative evaluation of ATB Fungus 2 and Sensititre Yeast One panels for testing in vitro Candida antifungal susceptibility

ATB Fungus 2 y SensititreYeastOne son métodos comerciales para el estudiode la sensibilidad in vitro de levaduras a los antifúngicos. La concordanciaentre estos dos métodos fue evaluada con un total de 133 aislamientos deCandida (60 Candida albicans, 18 Candida dubliniensis, 29 Candida glabrata y26 Candida krusei). La lectura de las CMIs se realizó para cada métododespués de 24 h de incubación a 36 ± 1 ºC. La reproducibilidadintralaboratorio de ambos métodos fue excelente ( 99%). La concordanciaglobal entre las CMIs de ATB Fungus 2 y Sensititre YeastOne 3 (en un rango± 2 diluciones) fue de 91,2-97,7% para anfotericina B, 5-fluorocitosina eitraconazol, y 82,7% para fluconazol. La concordancia por categorías cuandolos resultados de ATB Fungus 2 fueron comparados con los deSensititreYeastOne 3 fue de 93,2-98,5% para 5-fluorocitosina y anfotericina B,pero más baja para los triazoles (72,9-75,9%). Este método sencillo de realizarpuede ser una alternativa para uso de rutina en el laboratorio de microbiologíaclínica en el estudio de la sensibilidad de Candida spp(AU)

ATB Fungus 2 and SensititreYeastOne are commercial methods for antifungalsusceptibility testing of yeasts. The agreement between these two methodswas assessed with a total of 133 Candida strains (60 Candida albicans,18 Candida dubliniensis, 29 Candida glabrata, and 26 Candida krusei).MIC endpoints were established after 24 h of incubation at 36 ± 1 ºC by eachmethod. Intra-laboratory reproducibility of both methods was excellent( 99%). Overall agreement between ATB Fungus 2 and Sensititre YeastOne 3MICs (within 2 dilutions) was 91.2-97.7% for amphotericin B, 5-fluorocytosineand itraconazole, and 82.7% for fluconazole. The categorical agreement whenATB Fungus 2 results were compared to those by SensititreYeastOne 3 was93.2-98.5% for 5-fluorocytosine and amphotericin B, but lower for the triazoles(72.9-75.9%). This easy to perform method could be an alternative for routineuse in the clinical microbiology laboratory for susceptibility testing of commonCandida spp(AU)

Biofilm development by clinical isolates of Malassezia pachydermatis.

Malassezia pachydermatis fungemia has been reported in patients receiving parenteral nutrition. Biofilm formation on catheters may be related to the pathogenesis of this mycosis. We investigated the biofilm-forming ability of 12 M. pachydermatis strains using a metabolic activity plate-based model and electronic microscopic evaluation of catheter surfaces. All M. pachydermatis strains developed biofilms but biofilm formation showed variability among the different strains unrelated to their clinical origin. This study demonstrates the ability of M. pachydermatis to adhere to and form biofilms on the surfaces of different materials, such as polystyrene and polyurethane.

Usefulness of Candida ID2 agar for the presumptive identification of Candida dubliniensis.

CHROMagar Candida and Candida ID2 are widely used for the isolation and presumptive identification of Candida spp. based on the color of the colonies on these two media. We have studied the usefulness of these chromogenic media for differentiating Candida dubliniensis from Candida albicans isolates. One hundred isolates of C. dubliniensis and 100 C. albicans isolates were tested on Candida ID2, CHROMagar Candida (CHROMagar), and CHROMagar Candida reformulated by BBL. CHROMagar Candida and CHROMagar Candida BBL did not allow a clear differentiation of the two species based upon the shade of the green color of C. dubliniensis colonies. However, on Candida ID2, all C. dubliniensis isolates produced turquoise blue colonies whereas 91% of C. albicans colonies were cobalt blue. The sensitivity and the specificity for differentiating between C. dubliniensis fromC. albicans on Candida ID2 were 100% and 91%, respectively; whereas on CHROMagar Candida these values were 63% and 89% and on CHROMagar Candida BBL they were 18% and 98%. Candida ID2 agar provides a simple and accurate laboratory approach for the identification and differentiation of C. dubliniensis on the basis of the colony color.

Evaluation of the new chromogenic medium Candida ID 2 for isolation and identification of Candida albicans and other medically important Candida species.

The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis.

Supplementation of CHROMagar Candida medium with Pal's medium for rapid identification of Candida dubliniensis.

CHROMagar Candida medium is used for the isolation and identification of Candida species, but it does not differentiate Candida albicans from Candida dubliniensis. This differentiation can be achieved by using Pal's agar, which cannot be used in primary isolation. We have combined both media to obtain a new medium that can be used for the isolation and identification of C. dubliniensis in primary cultures.